The most important part of creating a series of children's books is coming up with a terrific idea – something with instant child appeal and the possibility of loads of plots.

It’s vital that you can describe the basic idea in just a few words. Think of the ones that are already successful, and you’ll see what I mean: teenage spy, princess with 4 ponies, secret unicorn, children who help fairies, school for princesses.

That strong idea will help you sell the series to an editor, help the editor sell it to the rest of the company, help the sales team sell it to bookshops and, eventually, help the bookshops sell it to children.

For a successful series idea, you need:

a strong main character or characters. Even if your idea involves a group of children (a team or club perhaps) try to focus in particularly on one or two of them. Young readers like characters that are older than them, not too perfect and a bit headstrong. They want someone who will dive in to try to solve a problem rather than dither around on the edges or always rely on an adult to get them out of trouble.

the possibility of lots of plots. This might come from moving your characters around (as in Astrosaurs or the Willard Price adventure books) or it might be other people entering into your characters world (like the different patients in Animal Ark). Alternatively your setting may manage to generate lots of stories without any outside influences at all.

as little influence from parents as possible. That’s why boarding school stories as so popular and why, over the years, so many successful children’s characters have been orphans. Hard-working parents who are too busy to interfere too much can be very useful.

Once you've got your idea, it's time to move on to developing and writing it. But you need to avoid the most common pitfalls. (I know this because I’ve fallen into nearly all of them.)

Pitfall no 1: Choosing an idea you don’t like enough
If your series is as success, you could end up writing it for a long time. Although it’s good to come up with an idea that’s very commercial, it’s very important that you should feel passionate about it too. So don’t create a series about a football team if you can’t stand the game.

Pitfall no 2 Too many characters in the first book
If you try to introduce too many characters at once, you’ll end up confusing your readers. This doesn’t mean you can’t have crowds of people in your story provided you don’t expect your readers to remember who they all are. So focus in on the crucial characters for the first story and introduce any others in later books. You’ll also make life easier for your readers if all the names are phonetic and each one startst with a different letter of the alphabet.

Pitfall no 3: Too long a time frame
Series books for 6-9 year olds are short so you have very few words to tell your story. If you set it over several weeks, you’ll have to skip chunks of time, but this is hard to do unless nothing happens during them. Setting stories in short time frames (2/3 days or less) makes for a much better pace, especially if you introduce some sort of time pressure. (That’s why evil villains always sets a clock to count off the seconds until the bomb explodes.)

Pitfall no 4: Painting yourself into a corner
When you start your series, you begin with a relatively empty slate, particularly with a fantasy. But everything you write lays down the rules for what follows. If it’s convenient for someone to be allergic to cats in book one, it may be a nuisance in a later one. And you can't suddenly make your character allergic to them in book 5, if they spent book 1 walking round with a kitten on their shoulder. Believe me – children will notice if you make mistakes.

As you write the stories, create a series bible with all the important details that you much keep constant from one book to the next. For my Pony-Mad Princess series, this includes the sex of all the ponies, their likes and dislikes and the fact that Ellie has a spiral staircase leading to her bedroom.

Pitfall no 5: Using up potential Christmas and Summer stories.
If your series is successful, you’ll sure to be asked to write a Christmas book or a Summer Special. So if you get an idea that would fit into either of these categories, tuck it away for later use.

Writing the Proposal
There are lots of different ways to do this. Here’s the way that’s worked for me.

Start with a one or two line description of your big idea. Enlarge on this for a paragraph or two to show how you intend to develop it. Then move on to sections describing

the target market

the length

the main selling points

Finally add
6 story lines - about one paragraph per story together with a working title- and the complete text of the first book